Place cumin in a Dutch oven; cook over medium heat 30 seconds or until toasted. Add water, chili powder, 3 teaspoons lemon juice, 1/4 teaspoon salt, oregano, chicken, broth, bay leaves, and garlic; bring to a boil. Partially cover, reduce heat to medium-low, and simmer 20 minutes or until chicken is done. Remove chicken from pan; place chicken in a bowl, and chill 15 minutes. Strain broth mixture through a sieve into a large bowl; discard solids. Remove chicken from bones; shred. Discard bones; set meat aside.
Return broth mixture to pan. Add potatoes; bring to a boil. Partially cover, reduce heat, and simmer 15 minutes or until tender. Add beans; simmer 5 minutes. Add chicken and shrimp; simmer 3 minutes or until shrimp are done. Remove from heat; stir in 2 teaspoons lemon juice, 1/4 teaspoon salt, onions, and cilantro.